File for band-saws



(No Model.)

J. E. EMERSON.

FILE FOR BAND SAWS.

No. 358,026. Patented Feb.22,1887.

UNITED STATES PATENT OFFICE.

JAMES E. EMERSON, OF BEAVER FALLS, PENNSYLVANIA.

FILE FOR BAND-SAWS.

SPECIFICATION forming part of Letters Patent No. 358,026, dated February22, 1887.

Application filed December 14,18E6. Serial No. 221,543. (No model.)

To all whom it may concern:

Be it known that I, JAMES E. EMERSON, a citizen of the United States,residing at Beaver Falls,in the county of Beaver and State ofPennsylvania, have invented certain new and useful Improvements in Filesfor Band Saws; and I do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

My invention relates to the construction of files, and has for itsobject the construction of files especially adapted for filing band-sawsin which the teeth are provided with concavities at their roots or baseson their front and rear edges.

Practical experience in the use of bandsaws has demonstrated that teethhaving right or acute angles to their roots or bases are liable to crackat that point, and the crack frequently extends far down into the blade,thus weakening it, and often renders it unfit for further use. Toovercome this difficulty, a standard tooth for bandsaws has been almostuniversally adopted, and this tooth, instead of having right or acuteangles formed at its root, is provided with a fillet or concavity infront and rear of the tooth. This change in the form of the tooth hasnecessitated the construction of a file to sharpen the saws, asordinarily it would require two files, one fiat and the other round, orthe use of an einerywheel to sharpen it.

My invention, therefore, consists in the con struction of a file, whichwill be hereinafter described, and particularly pointed out in theclaims.

In the accompanying drawings, which form a part of this specification,Figure 1 is a perspective of a file. Fig. 2 shows a section of aband-saw and a vertical cross-section of the file applied to the frontedge of one of the teeth. Fig. 3 shows a similar view with the fileapplied to the rear edge of one of the teeth.

Reference being had to the drawings and the letters marked thereon, Arepresents a file, a vertical cross-section of which describessubstantially a triangle or a triangular isosceles pyramid, in which (trepresents the base, 6 and c the sides, and d the apex. It will beobserved the teeth of the saw, and,by reference to Figs. 6c

2 and 3, it will be observed that the pitch of the tooth is about aneighth of an inch to one inch in the height of the tooth, as indicatedby the lines h i, and thatthe width of the side I) c of the file is morethan equal to the height of the tooth and about equal to the angular orrear side of the tooth. By this construction of a file all of the teethin a bandsaw can be kept at the same pitch and the shape of the teethpreserved without the use of an emery-wheel, as is the usual practice ofsharpening such saws.

Iam aware that files have been made which in cross-section representthree equal sides of a triangle with fiat and rounded corners at eachangle, and that angular files with a rounded base have beenSilOWll,'t1lld do not therefore claim such a construction; but,

Having fully described my invention, what I claim is 1. A filethc'crosssection of which represents substantially an isoscelestriangle, the sides of which are in height more than double the width ofthe base, and whose corners are curved, substantially as described, andas shown in the drawings.

2. A filo the sides of which are more than double the width of itswidest edge and the corners at the base, and the narrow edge of the filebeing rounded, substantially as described, and as shown in the drawings.

3. A file the crosssection of which is substantially an isoscelestriangle, the sides of which are formed at an angle of about an eighthof an inch to one inch and the corners of which and the upperedge arerounded,substantially as described, and as shown in the drawings.

In testimony whereof I aflix my signature in presence of two witnesses.

, JAMES E. EMERSON. lVitnesses:

CHAS. W. HANDY, I). G. REINoHL.

